This patch adds code that is already in ACPICA upstream, so applying
it can help to reduce the source code differences between Linux and
ACPICA upstream.

This code fragment is only useful for ACPICA utilities and no
functional changes to the Linux kernel should result from it.

[rjw: Changelog]
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>